Raymond step-tapered piles. These consist of a corrugated steel shell driven into the ground using a mandrel.

The shell consists of sections with variable diameters that increase from the tip to the pile head. A mandrel is a heavy, rigid steel tube shaped to fit inside the shell. The mandrel is withdrawn after the shell is driven and the shell filled with concrete. Raymond step-tapered piles are predecessors of drilled shafts and are still popular in the southern United States.